Nishioka T.¹, sugami M.¹, Fujimoto T.¹

The International Conference on Computational & Experimental Engineering and Sciences, Vol.1, No.3, pp. 119-126, 2007, DOI:10.3970/icces.2007.001.119

Abstract In this paper, the simulations of fatigue crack propagation and dynamic fracture path prediction are carried out for specimens containing circular holes or inclusions, using the moving finite element method based on Delaunay automatic triangulation. And, we compared the numerical results with the experimental results. More >

T. Nishioka¹, Y. Kobayashi¹, T. Fujimoto¹

CMES-Computer Modeling in Engineering & Sciences, Vol.17, No.3, pp. 231-238, 2007, DOI:10.3970/cmes.2007.017.231

Abstract First, for growing cracks in elastic-plastic materials, an incremental variational principle is developed to satisfy the boundary conditions near newly created crack surfaces. Then using this variational principle, a moving finite element method is formulated and developed, based on the Delaunay automatic triangulation. Furthermore, theoretical backgrounds on numerical prediction for fracture path of curving crack using T* integral are explained. Using the automatic moving finite element method, fracture-path prediction simulations are successfully carried out. More >

L. Dieng¹, A. Abdul-Latif², M. Haboussi, C. Cunat³

CMC-Computers, Materials & Continua, Vol.6, No.1, pp. 21-34, 2007, DOI:10.3970/cmc.2007.006.021

Abstract Being of particular interest in this work, a complicated phenomenon related to cyclic softening of metallic polycrystals is modeled. As in the Waspaloy, this phenomenon can take place when a non-proportional tension-torsion cyclic loading of 90° out-of-phase is followed, after cyclic steady state, by a uniaxial one (tension-compression) with the same maximum equivalent plastic strain. By using the DNLR (Distribution of Non Linear Relaxation) model recently proposed by the authors describing the cyclic plasticity of metals, a new extension is here developed. It is recognized that such an extension can satisfactorily reproduce this softening phenomenon. More >

S. K. Panthi^1,2, N. Ramakrishnan², K. K. Pathak², J. S. Chouhan³

CMC-Computers, Materials & Continua, Vol.6, No.1, pp. 13-20, 2007, DOI:10.3970/cmc.2007.006.013

Abstract One of the important features of flanging process is elastic recovery during unloading leading to springback. The elastic recovery is associated with various tool and material parameters. It is difficult to analytically predict the elastic recovery accurately owing to the complex material deformation behavior. In this investigation, a commercially available Finite Element software is used for elasto-plastic analysis of flanging process. The springback is studied varying geometrical, material and friction parameters. The results of the simulation are validated with a few published experimental results. More >

Pierre I. Karakiewicz^1,2, Felix K.-H. Chun^2,3, Alberto Briganti², Paul Perrotte¹, Michael McCormack¹, François Bénard¹, Luc Valiquette¹, Markus Graefen³, Fred Saad¹

Canadian Journal of Urology, Vol.13, Suppl.2, pp. 18-25, 2006

Abstract Introduction: Several nomograms have been developed to predict PCa related outcomes. Neural networks represent an alternative.
Methods: We provide a descriptive and an analytic comparison of nomograms and neural networks, with focus on PCa detection.
Results: Our results indicate that nomograms have several advantages that distinguish them from neural networks. These are both quantitative and qualitative.
Conclusion: In the field of PCa detection, nomograms appear to outweigh the benefits of neural networks. However, the neural network methodology represents a valid alternative, which should not be underestimated. More >

Robert K. Nam¹, Ants Toi², Laurence H. Klotz¹, John Trachtenberg³, Michael A. S. Jewett³, Andrew Loblaw⁴, Greg R. Pond¹, Marjan Emami¹, Linda Sugar⁵, Joan Sweet⁶, Steven A. Narod⁷

Canadian Journal of Urology, Vol.13, Suppl.2, pp. 2-10, 2006

Abstract Background: There is a large amount of confusion in interpreting prostate specific antigen (PSA) values for prostate cancer. More precise risk assessments for prostate cancer detection are needed for men faced with an abnormal PSA.
Methods: We studied a sample of 2637 men who underwent a prostate biopsy for an abnormal digital rectal exam (DRE) or PSA. Using factors including age, ethnicity, family history of prostate cancer, previous negative biopsy, presence of voiding symptoms, prostate volume, DRE and PSA, we constructed nomograms to predict the probability of prostate cancer at biopsy.
Results: Of the 2637 men, 1282 men… More >

Amado Alvarez^1,2, Enrique Rubiños Panta¹, Francisco Gavi Reyes¹, Juan José Alarcón Cabañero², Elizabeth Hernández Acosta³, Carlos Ramírez Ayala¹, Enrique Mejía Saenz¹, Francisco Pedrero Salcedo², Emilio Nicolas Nicolas², Enrique Salazar Sosa⁴

Phyton-International Journal of Experimental Botany, Vol.75, pp. 71-83, 2006, DOI:10.32604/phyton.2006.75.071

Abstract A water quality index as a standardized method to compare the category in an integral way, between locations and through time, of the different water, river and stream storages of the Amajac river basin was developed. In addition, it is possible to predict the degree of contamination and establish planning strategies in the management of the water resources for the river basin in issue. The used methodology was based in the quantitative expression of water quality. Three samplings were made (2005-2006) and Dissolved Oxygen, Coliform in feaces, pH, Oxygen Biochemical Demand, Nitrates, Total Phosphorus, Turbidity… More >

E. Abhilash¹, M.A. Joseph¹, Prasad Krishna¹

FDMP-Fluid Dynamics & Materials Processing, Vol.2, No.3, pp. 211-220, 2006, DOI:10.3970/fdmp.2006.002.211

Abstract Aluminium-Silicon alloys are in high de-mand as an engineering material for automotive,aerospace and other engineering applications. Mechanical properties of Al-Si alloys depend not only on chemical composition but also more importantly on microstructural features such as dendritic alpha-aluminiumphase and eutectic silicon particles. As an additive to Al-Si alloys, sodium improves mechanical properties byforming finer and fewer needles like microstructures.Thus, prediction of the macro and microstructures obtained at the end of the solidification is of great interest for the manufacturer of aluminium alloys. Neuralnetworks are sophisticated nonlinear regression routinesthat, when properly “trained”, allow for the identificationof More >

Jae Bong Lee¹, Jai Hak Park¹, Sung Ho Lee², Hong-Deok Kim², Han-Sub Chung²

CMES-Computer Modeling in Engineering & Sciences, Vol.11, No.1, pp. 9-16, 2006, DOI:10.3970/cmes.2006.011.009

Abstract The growth of stress corrosion cracks in steam generator tubes is predicted using the Monte Carlo simulation and statistical approaches. The statistical parameters that represent the characteristics of crack growth and crack initiation are derived from in-service inspection (ISI) non-destructive evaluation (NDE) data. Based on the statistical approaches, crack growth models are proposed and applied to predict crack distribution at the end of cycle (EOC). Because in-service inspection (ISI) crack data is different from physical crack data, a simple method for predicting the physical number of cracks from periodic in-service inspection data is proposed in More >

T. Nishioka¹, S. Tchouikov¹, T. Fujimoto¹

CMC-Computers, Materials & Continua, Vol.3, No.3, pp. 147-154, 2006, DOI:10.3970/cmc.2006.003.147

Abstract In this study, phenomena of multiple branching of dynamically propagating crack are investigated numerically. The complicated paths of cracks propagating in a material are simulated by moving finite element method based on Delaunay automatic triangulation (MFEM BODAT), which was extended for such problems. For evaluation of fracture parameters for propagating and branching cracks switching method of the path independent dynamic J integral was used. Using these techniques the generation phase simulation of multiple dynamic crack branching was performed. Various dynamic fracture parameters, which are almost impossible to obtain by experimental technique alone, were accurately evaluated. More >